Damping device

ABSTRACT

A damping device, in particular, for damping or preventing pressure shocks, such as pulsations, in hydraulic supply circuits, preferably in the form of a silencer, having a damping housing ( 1 ) surrounding a damping chamber ( 19 ), which includes at least one fluid inlet ( 11 ) and at least one fluid outlet ( 13 ), as well as a fluid receiving chamber ( 19 ) extending between the fluid inlet and fluid outlet, wherein, during operation of the device, a fluid flow coming from the fluid inlet ( 11 ) in a through-flow direction ( 15 ) traverses the damping chamber ( 19 ) in the direction of the fluid outlet ( 13 ), and wherein at least parts of the fluid receiving chamber ( 19 ) extend in at least one direction of extension transverse to the through-flow direction ( 15 ), is characterized in that the fluid receiving chamber ( 19 ) is located directly adjacent to the fluid inlet ( 11 ) and the fluid outlet ( 13 ).

The invention relates to a damping device, in particular, for damping orpreventing pressure shocks, such as pulsations, in hydraulic supplycircuits, preferably in the form of a silencer having a damping housingsurrounding a damping chamber, which includes at least one fluid inletand at least one fluid outlet, as well as a fluid receiving chamberextending between the fluid inlet and fluid outlet, wherein, duringoperation of the device, a fluid flow coming from the fluid inlet in athrough-flow direction traverses the damping chamber in the direction ofthe fluid outlet, and wherein at least parts of the fluid receivingchamber extend in at least one direction of extension transverse to thethrough-flow direction.

Damping devices of this type are prior art. Such hydraulic dampers, alsocalled noise dampers or silencers, are used to reduce the vibrationsgenerated by pressure pulsations, which are periodically imparted to arelated hydraulic system, in particular, as a result of the operation ofthe hydraulic pumps. As shown in the document DE 102 17 080 C1, theknown damping devices of this kind have a damping housing in the form ofa circular cylinder, which is spherically rounded at both axial endsections, wherein a fluid inlet and a fluid outlet are situated at eachend section coaxially to the cylindrical axis. In these damping devices,the damping chamber, which the fluid flow traverses from the fluid inletto the fluid outlet, is provided in the form of a damping tube, whichextends coaxially between the fluid inlet and the fluid outlet, andincludes openings in the tube wall to the fluid chamber surrounding thetube. The fluid chamber, in conformity with the cylinder diameter, isexpanded radially relative to the axial through-flow directionpredefined by the damping tube.

Based on this prior art, the stated object of the invention is toprovide a damping device of the kind under consideration, which, beingsimple in design, is distinguished by an advantageous operatingbehavior.

This object is achieved by a damping device according to the invention,which has the features of patent claim 1 in its entirety.

According to the characterizing portion of claim 1, an essentialcharacteristic of the invention is that the fluid receiving chamber isdirectly adjacent to the fluid inlet and to the fluid outlet. In thedesign, simplified by the omission of the damping tube, a single cavityforms a resonator system formed together from a damping chamber and afluid chamber. The device according to the invention is distinguishednot only by a simplified design, but also by an enhanced efficiency interms of its fluid volume and weight. As compared to known silencers ofthis kind, in which an amplification of pulsations between the pump andentry to the silencer may result, this risk is also significantlyreduced in the case of the invention.

A particularly high efficiency of the damping effect may be achieved inexemplary embodiments, in which the fluid receiving chamber forms acavity in the form of a disk within the damping housing. The disk shapein this case may be cylindrical or designed as a polygon or may have anyother non-circular shape.

The configuration in this case may be particularly advantageouslyachieved in that the cavity is closed by two partition walls of thedamping housing extending parallel to one another, wherein parts of thefluid inlet and fluid outlet are aligned with these partition walls inthe damping housing. In such a configuration, the diameter of the fluidinlet and fluid outlet, formed as damping housing bores, may be of equalsize and may correspond to the distance between the two partition walls.

In a particularly advantageous exemplary embodiment of the invention, inwhich the damping housing is designed in multiple parts, the followingcomponents may be provided.

-   -   a pot-like bottom part, which accommodates a disk-like central        recess with the one partition wall and the fluid inlet and fluid        outlet, and    -   a cover part designed as a flange, which, together with the        other partition wall as part of an engagement connection with        the cover part affixed to the bottom part, is engaged in the        central recess such that it is aligned therewith.

To seal the cavity from the environment, a sealing means, in particular,in the form of a sealing ring inserted in a circumferential groove maybe disposed on the engagement connection of the cover part, which formsa seal at the central recess of the pot-like bottom part.

For a pressure-resistant design of the damping housing, the cover partmay include multiple through-bores diametrically opposite its verticalaxis, through which fixing screws are passed to affix the cover part tothe bottom part.

The fixing screws are preferably disposed uniformly along an outerperiphery on the damping housing, which encompasses the disk-like fluidreceiving chamber, while leaving the areas of the fluid inlet and fluidoutlet exposed.

To connect to a particular hydraulic system, a seating for a sealingring, which encompasses the fluid inlet and/or the fluid outlet, may beprovided at the fluid inlet and/or at the fluid outlet in the dampinghousing. The damping housing may be affixed to third components in themanner of a fixing block by means of multiple fixing bolts, whichsurround the area of the fluid inlet and/or fluid outlet.

The invention is explained In detail below with reference to anexemplary embodiment depicted in the drawings, in which:

FIG. 1 shows a perspective diagonal view of an exemplary embodiment ofthe damping device according to the invention, drawn reduced to a scaleof approximately 1:3 as compared to a practical embodiment;

FIG. 2 shows a longitudinal section of the exemplary embodiment drawnslightly reduced as compared to a practical embodiment;

FIG. 3 shows a top view of the bottom part of the damping housing of theexemplary embodiment in the scale of FIG. 2 and drawn partially cutaway;

FIG. 4 shows a sectional representation along the section line IV-IV ofFIG. 3;

FIG. 5 shows a partial view of merely the connection area of the dampinghousing of the exemplary embodiment, which includes the fluid outlet.

FIG. 6 shows a partial view corresponding to FIG. 5 of the connectionarea, which includes the fluid entry;

FIG. 7 shows a longitudinal section of merely the cover part of thedamping housing drawn on a larger scale as compared to FIGS. 2 through4.

FIG. 8 shows a perspective diagonal view of the cover part, as viewedtoward the inner side, which forms an engagement connection.

FIGS. 1 and 2 show the exemplary embodiment of the damping device in theassembled state, The damping housing 1, depicted as closed in thesefigures, comprises two main parts, namely, a bottom part 3, which isdepicted separately in FIGS. 3 and 4, as well as a cover part 5, whichis shown separately in FIGS. 7 and 8. The bottom part 3 and cover part 5each have the same contour, so that in the assembled state (FIG. 1) theyare circumferentially aligned with one another, wherein, the contourcorresponds to a circle, but which has a planar flat portion 7 and 9 ontwo sides diametrically opposite one another. The fluid inlet 11 of thedamping housing 1 is situated in the part of the flat portion 7associated with the bottom part 3, and the fluid outlet 13 is situatedin the part of the flat portion 9 associated with the bottom part 3,wherein the inlet 11 and the outlet 13 are aligned flush with the axisof the through-flow direction identified by 15 in FIG. 3. Four threadedbores 16 each are situated in the flat portions 7 and 9, and aredisposed in the corner areas of the rectangular-shaped flat portions 7and 9, and which enable the damping housing 1 to be fixed by means ofthreaded bolts 17 (FIG. 1).

Within the damping housing 1, the fluid receiving chamber extendingbetween the fluid inlet 11 and the fluid outlet 13, which actsconcurrently as a damping chamber, is formed by means of a cavity in theform of a disk-like space 19. The latter has the shape of a circulardisk in the form of a flat circular cylinder, the one disk face of whichis bordered by a flat wall 21, which forms the inner bottom face thereofin the bottom part 3, which is formed in a pot-like manner by a central,hollowed central recess 41. As is most clearly seen from FIG. 4, thebottom part 3 delimits, with the inner side wall 22 of the pot, thecircular diameter of the circular disk-like hollow space 19 in relationto the central axis 23. The fluid inlet 11 and fluid outlet 13 are eachformed by bores in the flat portions 7 and 9, merging flush in thehollow space 19 with the partition wall 21, which forms the interiorbottom of the pot.

The upper partition wall of the disk-shaped hollow space 19 in FIG. 2 isformed by planar, circular wall 25 on the cover part 5. In the assembledstate, see FIG. 2, the wall 25, as does the other partition wail 21,aligns with the respective fluid inlet 11 and fluid outlet 13. If, in apractical exemplary embodiment, the fluid inlet 11 and fluid outlet 13are formed, for example, by one bore each 12 mm in diameter, thedisk-shaped hollow-space 19 has a depth of 12 mm. in such an exemplaryembodiment, the inner diameter of the hollow space 19 may be in therange of 100 mm, in the case of an outer diameter of the damping housing1, outside the flat portions 7, 9, in the range of 160 mm, for example.

As shown in FIGS. 7 and 8, the cover part 5 includes a flange part 27with fastening holes 29. The flange part 27 has the same contour as thebottom part 3, thus, is circular, apart from the flat portions 7 and 9,resulting in the uninterrupted outer shape for the entire assembleddevice, as is depicted in FIG. 1. The fastening holes 29, as shown inFIG. 8, are provided on an arc, each beyond the area of the flatportions 7, 9. Threaded bores 31 matching the fastening bores 29 areprovided In the bottom part 3, which are formed as blind holes in theplanar upper side 33 of the bottom part 3, and provided for fasteningscrews 35, which penetrate the fastening holes 29 in order to affix thecover part 5 with its flange surface 37 to the upper side 33 on the openside of the pot of the bottom part 3.

In the fixed state, a cylindrical engagement connection extendingcoaxially from the flange surface 37 of the cover part 5 engages in thecenter recess 41 in the bottom part 3, which is delimited by the innerside wall 22 of the pot of the bottom part 3. This engagement in thescrew-connected state is shown in FIG. 1, wherein the wall 25 at the endof the engagement connection 39 forms the upper partition wall of thehollow space 19. A sealing ring 45 is inserted in an annular groove 43incorporated in the side wall of the engagement connection 39 forsealing the hollow space 19 with respect to the cover part 5. As shownin FIG. 6, an annular groove 47 for a sealing element, which provides aseal at the connection point, is provided on the flat portion 7associated with the fluid inlet 11. It is understood that acorresponding sealing arrangement may be similarly provided on the flatportion 9 associated with the fluid outlet. Due to the symmetricalhousing design, it is also possible to switch the inlet and outlet side,having optionally modified sealing geometries, with one another. Thedisk-shaped damping chamber, having a cavity extended in a directiontransverse to the actual through flow direction, results in a silencerhaving high efficiency, which is low in weight relative to itspredefinable flow volume. Furthermore, only a minimal amplification, ifany at all, occurs between the silencer and a hydraulic pump connectedto it.

1. A damping device, in particular, for damping or preventing pressureshocks, such as pulsations, hi hydraulic supply circuits, preferably inthe form of a silencer, having a damping housing (1) surrounding adamping chamber (19), Which has at least one fluid inlet (11) and atleast one fluid outlet (13), as well as a fluid receiving chamber (19)extending between the fluid inlet and fluid outlet, wherein, duringoperation of the device, a fluid flow coming from the fluid inlet (11)in a through-flow direction (15) traverses the damping chamber (19) inthe direction of the fluid outlet (13), and wherein at least parts ofthe fluid receiving chamber (19) extend in at least one direction ofextension transverse to the through-flow direction (15), characterizedin that the fluid receiving chamber (19) is located directly adjacent tothe fluid inlet (11) and the fluid outlet (3).
 2. The damping deviceaccording to claim 1, characterized in that the fluid receiving chamberembodies a hollow space (19) disk-like in design within the dampinghousing (1).
 3. The damping device according to claim 1, characterizedin that the disk-like hollow space (19) is cylindrical or designed as apolygon.
 4. The damping device according to claim 1, characterized inthat the fluid receiving chamber (19) between the fluid inlet (11) andthe fluid outlet (13) is designed to be unobstructed in such a way thatit is kept free of damping elements.
 5. The damping device according toclaim 1, characterized in that the hollow space (19) is also closed offby two partition walls (21, 25) of the damping housing (1) extendingparallel to one another, and that parts of the fluid inlet (11) and ofthe fluid outlet (13) are aligned with these partition walls (21, 25) mthe damping housing (1).
 6. The damping device according to claim 1,characterized in that the diameter of the fluid inlet (11) and the fluidoutlet (13), designed as damping housing bores, is the same size andcorresponds to the distance between the two partition walls (21, 25). 7.The damping device according to claim 1, characterized in that thedamping housing (1) is designed with multiple parts having a pot-likebottom part (3), which accommodates a disk-like central recess (41) withthe one partition wall (21) as well as the fluid inlet (11) and fluidoutlet (13), and a cover part designed as a flange (5), which, togetherwith the other partition wall (25) as part of an engagement connection(39) with the cover part (5) affixed to the bottom part (3), is engagedin the central recess (41) such that it is aligned therewith.
 8. Thedamping device according to claim 1, characterized in that a sealingmeans, in particular, in the form of a sealing ring (45) inserted in acircumferential groove (43) is disposed on the engagement connection(39) of the cover part (5), and which seals the hollow space (19) as acomponent of the central recess (41) from the environment.
 9. Thedamping device according to claim 1, characterized in that the coverpart (5) includes multiple through-bores (29) diametrically opposite itsvertical axis through which fixing screws (35) are passed to affix thecover part (5) to the bottom part (3).
 10. The damping device, accordingto claim 1, characterized in that the fixing screws (35) are disposeduniformly along an outer periphery on the damping housing, whichencompasses the disk-like fluid receiving chamber (19), while leavingthe areas (7, 9) of the fluid inlet (11) and fluid outlet (13) exposed.11. The damping device according to claim 1, characterized in that aseating (47) for a sealing ring is provided at the fluid inlet (11)and/or at the fluid outlet (13) in the damping housing (1), whichsealing ring encompasses the fluid inlet (11) and/or the fluid outlet(13).
 12. The damping device according to claim 1, characterized in thatthe damping housing (1) may be affixed to third components in the mannerof a fixing block with multiple fixing bolts (17), which surround thearea (7, 9) of the fluid inlet (11) and/or fluid outlet (13).